Automatic clutches or servoclutches are, for example, known from the text entitled "Automotive Handbook", third edition, (1993), pages 538 and 539 as well as from German patent application P 195 40 921 (corresponding to International patent application PCT/DE 96/01347, filed Jul. 23, 1996). Automatic clutches in combination with electronic control apparatus provide either an automated start from standstill or, together with a servo-actuated shifting mechanism, a fully automatic transmission. In such automatic clutches, the disengagement and engagement of the clutch is generally actuated via a servodrive.
In addition to such automatic clutches, automatic transmissions are known wherein the transmission ratio can be changed in response to a drive signal. Such automatic transmissions can, in a manner known per se, be connected to the motor of the vehicle via a hydraulic converter.
It is known that the shifting pressure or the fluctuations in the drivetrain occurring under these circumstances can be attenuated utilizing the converter. The shifting pressure arises with the change of the transmission ratios. The converter can be bridged by a known converter bridge clutch or the bridge can be removed. At higher vehicle speeds or in the upper gears of the transmission, this converter bridge clutch is mostly engaged. In this way, slip losses of the torque converter are prevented and, in this way, the fuel consumption is reduced; however, the effect of the converter in attenuating fluctuations in the drivetrain is not provided when the converter bridge clutch is engaged. In addition, the slip of such converter clutches can be controlled.
Furthermore, it is known to provide a motor control apparatus for controlling the motor of a vehicle by means of which the motor output torque is controlled, for example, in dependence upon the following: driver command, motor operating parameters and additional variables representing or influencing the operation of the vehicle. German patent publication 4,321,333 discloses an electronic accelerator pedal system wherein measures for reducing fluctuations in the drivetrain during the transition from the overrun phase to the drive phase are provided. These measures include that the transition from the overrun phase into the tractive phase is detected and that, when a transition is detected, the execution of the command of the driver for adjusting the power of the internal combustion engine is delayed.